It was not the only goal of the match that benefited from a touch of fortune.
The strike should have settled the Hammers but instead their opponents, who have won their last five league and cup matches, grabbed the tie by the scruff of the neck.
Burly journeyman Dele Adebola proved to be a nuisance for defenders Danny Gabbidon and Herita Ilunga, while man-of-the-moment Lewis McGugan and Chris Cohen were beginning to combine well for the visitors on the right.
Their equaliser came courtesy of Adebola, who timed his run to perfection en route to picking up David McGoldrick's pull-back and slotting past Rob Green in the West Ham goal.
McGugan then tried to add to his own goal of the season collection with a volley from inside the area that went a couple of feet over a relieved Green.
However, luck deserted the Hammers when the England keeper was forced to parry a header from his own team-mate Ilunga and the loose ball was bundled in by McGoldrick.
The lead lasted two minutes and on this occasion it was Forest who were on the wrong end of a fluke.
Understandably, Obinna did not celebrate his second, which started out as a cross from way out on the right but ended up flying over the head of Camp and into the goal.
There was more goalmouth action to follow moments before the interval, Mark Noble coming close to putting the the home side ahead when he forced a great save from Camp, before the east Londoners finally took the lead again shortly after the restart.
On this occasion the ball was fed back into the crowded area from a cleared corner and defender Joel Lynch, who had performed well up to that point, pulled back Winston Reid, who was about to shoot.
After a gentleman's agreement, hat-trick hungry Obinna was handed the duties of putting the West Ham ahead, which he did with a well-placed kick.
On this occasion the Hammers did settle and Forest had Camp to thank for keeping the deficit at just three.
First Frederic Piquionne had a low shot from 25 yards beaten away by the 26-year-old, before Mexican Pablo Barrera struck a shot with the outside of his boot that had to be tipped over.
Forward Freddie Sears, who deserved a goal for his limitless endeavour on the day, then forced Camp to make another fabulous save with a fierce strike.
There was slight panic among the West Ham backline in the last few minutes when Green, largely untroubled in the second half, produced a good save to deny Chris Gunter, while McGoldrick headed two yards wide from a corner.
But the Hammers held on for a result which may soften the pain of their Carling Cup semi-final exit at Birmingham in midweek.
West Ham manager Avram Grant:
"It was very disappointing, the result on Wednesday, [Carling Cup semi-final defeat against Birmingham] but the most important thing is the reaction and it was very good.
"We didn't play well in the first half but in the second half we dominated. It's always good to play at home, they know how to support us and push us. I hope to be in the quarter-finals and then it will be interesting.
"But our target is the league, that is the most important thing, but winning in the FA Cup or the Carling Cup is also a good feeling."
Nottingham Forest boss Billy Davies:
"It's nice to come to the academy of football and play the way we did in the first half. We lost a terrible goal after two minutes or so but then deservedly got in front and it looked as if their second goal was fortunate.
"We played fantastic football in the first 45 minutes, flowing, chances galore. In the second half we gave away a goal and after that we were chasing things.
"I am proud of the players. We showed fantastic stuff, but in the end it was down to experience."
90:00+4:26 The referee brings the game to a close.
90:00+3:28 David McGoldrick produces a mishit right-footed shot from deep inside the penalty area which goes wide of the right-hand post.
90:00+1:34 Lewis McGugan concedes a free kick for a foul on Victor Obinna. Zavon Hines takes the direct free kick.
89:36 Joel Lynch produces a left-footed shot from outside the penalty box and misses right.
89:36 Substitution Zavon Hines on for Pablo Barrera.
86:02 Substitution Frederic Piquionne goes off and Frank Nouble comes on.
85:31 Chris Gunter takes a shot. Save by Robert Green.
83:07 Free kick awarded for a foul by Nathan Tyson on Winston Reid. Robert Green restarts play with the free kick.
82:01 Corner taken right-footed by Lewis McGugan to the near post, Headed effort from close range by David McGoldrick goes wide
left of the goal.
77:09 Substitution (Nottm Forest) makes a substitution, with Garath McCleary coming on for Paul McKenna.
73:40 Substitution Mark Noble leaves the field to be replaced by Luis Boa Morte.
70:32 Freddie Sears takes a shot. Lee Camp makes a save. Herita Ilunga takes the inswinging corner, save by Lee Camp.
68:59 Inswinging corner taken by Chris Cohen from the right by-line, clearance made by Daniel Gabbidon. Inswinging corner taken
from the right by-line by Chris Cohen, save made by Robert Green.
67:49 Robert Earnshaw takes a shot from just outside the penalty area which clears the crossbar.
67:49 Substitution (Nottm Forest) makes a substitution, with Nathan Tyson coming on for Radoslaw Majewski.
66:20 Frederic Piquionne takes a shot. Save by Lee Camp.
65:33 Freddie Sears produces a right-footed shot from inside the area that clears the crossbar.
65:33 Substitution Robert Earnshaw on for Dele Adebola.
64:05 Chris Gunter is penalised for handball and concedes a free kick. Mark Noble takes the free kick.
64:05 Booking Chris Gunter goes into the book for unsporting behaviour.
61:46 Pablo Barrera takes a shot. Save by Lee Camp. Inswinging corner taken by Herita Ilunga from the right by-line.
60:54 Shot by Frederic Piquionne. Lee Camp makes a save.
59:49 Centre by Freddie Sears, clearance made by Paul McKenna. Mark Noble takes the inswinging corner, Dele Adebola makes a clearance.
58:29 Corner taken left-footed by Chris Cohen from the right by-line to the near post, clearance made by Frederic Piquionne.
58:05 Mark Noble challenges Chris Gunter unfairly and gives away a free kick. Chris Gunter takes the free kick.
55:24 Free kick awarded for a foul by David McGoldrick on Victor Obinna. Free kick crossed right-footed by Mark Noble.
52:19 Lewis McGugan has shot on goal from just outside the area which goes wide of the right-hand upright.
51:37 Winston Reid fouled by Joel Lynch, the ref awards a Penalty. Assist by Winston Reid.
51:37 GOAL - Victor Obinna:West Ham 3 - 2 Nott'm Forest Victor Obinna scores a penalty. West Ham 3-2 Nottm Forest.
50:52 Booking Booking for Joel Lynch for unsporting behaviour.
50:01 Corner taken by Mark Noble, clearance made by Wes Morgan.
48:33 Foul by Dele Adebola on Daniel Gabbidon, free kick awarded. Robert Green takes the direct free kick.
47:48 Effort from outside the penalty area by Chris Cohen goes wide left of the goal.
46:47 Shot by David McGoldrick from outside the box goes over the target.
46:07 Chris Cohen challenges Mark Noble unfairly and gives away a free kick. Direct free kick taken by Mark Noble.
45:01 The match restarts for the second half.
45:00+2:02 The referee calls an end to the first half.
44:29 Victor Obinna has shot on goal from just outside the box which goes wide of the right-hand upright.
43:42 Corner from the left by-line taken by Mark Noble, clearance made by Radoslaw Majewski.
43:21 Short corner taken by Mark Noble from the left by-line.
42:58 Assist on the goal came from Mark Noble.
41:57 A cross is delivered by Victor Obinna,
41:57 GOAL - Victor Obinna:West Ham 2 - 2 Nott'm Forest A goal is scored by Victor Obinna from outside the penalty area to the top left corner of the goal. West Ham 2-2 Nottm Forest.
39:35 Free kick awarded for an unfair challenge on Chris Gunter by Herita Ilunga. Free kick crossed left-footed by Chris Cohen.
39:35 GOAL - David McGoldrick:West Ham 1 - 2 Nott'm Forest David McGoldrick finds the net with a headed goal from close range. West Ham 1-2 Nottm Forest.
37:46 Inswinging corner taken from the left by-line by Mark Noble, save by Lee Camp.
36:38 Corner taken by Chris Cohen from the right by-line, Joel Lynch has a headed effort at goal from close range which goes wide
of the left-hand post.
35:19 Shot on goal by Freddie Sears from just inside the area clears the crossbar.
32:41 Free kick awarded for a foul by Joel Lynch on Mark Noble. Mark Noble takes the free kick.
30:46 Foul by Frederic Piquionne on Lee Camp, free kick awarded. Free kick taken by Lee Camp.
29:58 Corner taken by Mark Noble from the left by-line to the near post, Luke Chambers manages to make a clearance.
26:27 Inswinging corner taken from the right by-line by Herita Ilunga, Dele Adebola makes a clearance.
23:40 Joel Lynch has an effort at goal from just outside the penalty box which goes wide of the left-hand post.
21:37 Free kick awarded for an unfair challenge on Chris Cohen by Frederic Piquionne. Free kick crossed by Chris Cohen.
20:35 Corner taken by Chris Cohen played to the near post, Radoslaw Majewski takes a shot. Winston Reid gets a block in. Chris Cohen
takes a inswinging corner to the near post, clearance by Frederic Piquionne.
18:47 David McGoldrick fouled by Daniel Gabbidon, the ref awards a free kick. Radoslaw Majewski has an effort direct from the free
kick, Daniel Gabbidon gets a block in. Corner taken right-footed by Lewis McGugan, save by Robert Green.
18:47 Booking Daniel Gabbidon receives a caution.
17:25 Assist by David McGoldrick.
17:25 GOAL - Dele Adebola:West Ham 1 - 1 Nott'm Forest Dele Adebola scores a goal from inside the penalty box to the bottom right corner of the goal. West Ham 1-1 Nottm Forest.
14:42 Winston Reid challenges Dele Adebola unfairly and gives away a free kick. Free kick crossed right-footed by Lewis McGugan
from left channel, clearance made by Radoslav Kovac.
11:35 Mark Noble gives away a free kick for an unfair challenge on Radoslaw Majewski. Lewis McGugan has a direct shot on goal from
the free kick.
9:02 David McGoldrick handles the ball and concedes a free kick. Robert Green restarts play with the free kick.
7:55 Free kick awarded for an unfair challenge on Chris Cohen by Frederic Piquionne. Chris Cohen restarts play with the free kick.
7:10 Lewis McGugan produces a right-footed shot from just outside the area that goes wide left of the goal.
4:41 Lewis McGugan has an effort at goal from deep inside the area missing to the left of the goal.
3:26 Freddie Sears takes a shot. Wes Morgan gets a block in. Lars Jacobsen decides to take a short corner. Mark Noble takes a shot.
The assist for the goal came from Mark Noble.
3:26 GOAL - Victor Obinna:West Ham 1 - 0 Nott'm Forest Victor Obinna finds the net with a goal from inside the area to the bottom left corner of the goal. West Ham 1-0 Nottm Forest.
1:17 Shot from just outside the box by Freddie Sears misses to the right of the goal.
0:00 The match gets underway.
Live text and data provided by The Press Association.
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